Here is the full list of all 52 Ys: Memories of Celceta achievements. It takes around 50-60 hours to unlock all of the achievements on Windows.
Acquired all achievements.
Purchased every piece of info from Mouse.
Cleared the game on Nightmare difficulty.
Acquired at least one of every item.
Restored all lost memories.
Discovered every resource point.
Proved your skill as a merchant.
Conquered Boss Rush.
Conquered Boss Rush without a single retry.
Defeated a boss in Time Attack in thirty seconds or less.
Defeated a boss in Time Attack without taking damage.
Completed the main story.
Filled out all monster details in journal.
Overcame Gruda's trial.
Opened every treasure chest.
Mastered every skill.
Played extensively as Karna.
Played extensively as Ozma.
Defeated a rare golden foe.
Opened the door to the Temple of the Sun.
Defeated the ruler of the Great Forest.
Completed the Map of Celceta.
Successfully completed every quest.
Endured all of Zara's tickle sessions.
Filled out all material details in journal.
Played extensively as Calilica.
Acquired both halves of the Mask of the Moon.
Enhanced a weapon or armor to its limit.
Amassed one million gold.
Cleared all obstructed paths.
Found all of Mishy's hiding spots.
Arrived in the ruined capital, Elduke.
Played extensively as Frieda.
Walked an extraordinary total distance.
Achieved five hundred Skill Finishes.
Befriended all animals.
Located the underground village of Danan.
Successfully used Flash Move fifty times.
Successfully used Flash Guard fifty times.
Reunited with Eldeel at the Tower of Providence.
Played extensively as Duren.
Defeated two thousand enemies.
Successfully arrived in the Primeval Lands.
Achieved one thousand Aerial Combos.
Achieved five hundred Excellent Kills.
Resolved the polluted river dilemma.
Defeated Duren in one-on-one combat.
Solved the mystery of the missing villagers.
Played extensively as Adol.
Discovered a settlement in the Great Forest.
Successfully rescued the trapped miners.
Began your adventure in Celceta.